Trial-level analysis of progression-free survival and response rate as end points of trials of first-line chemotherapy in advanced ovarian cancer

Modelling approaches for histology-independent cancer drugs to inform NICE appraisals: a systematic review and decision-framework

BACKGROUND

The first histology-independent marketing authorisation in Europe was granted in 2019. This was the first time that a cancer treatment was approved based on a common biomarker rather than the location in the body at which the tumour originated. This research aims to explore the implications for National Institute for Health and Care Excellence appraisals.

METHODS

Targeted reviews were undertaken to determine the type of evidence that is likely to be available at the point of marketing authorisation and the analyses required to support National Institute for Health and Care Excellence appraisals. Several challenges were identified concerning the design and conduct of trials for histology-independent products, the greater levels of heterogeneity within the licensed population and the use of surrogate end points. We identified approaches to address these challenges by reviewing key statistical literature that focuses on the design and analysis of histology-independent trials and by undertaking a systematic review to evaluate the use of response end points as surrogate outcomes for survival end points. We developed a decision framework to help to inform approval and research policies for histology-independent products. The framework explored the uncertainties and risks associated with different approval policies, including the role of further data collection, pricing schemes and stratified decision-making.

RESULTS

We found that the potential for heterogeneity in treatment effects, across tumour types or other characteristics, is likely to be a central issue for National Institute for Health and Care Excellence appraisals. Bayesian hierarchical methods may serve as a useful vehicle to assess the level of heterogeneity across tumours and to estimate the pooled treatment effects for each tumour, which can inform whether or not the assumption of homogeneity is reasonable. Our review suggests that response end points may not be reliable surrogates for survival end points. However, a surrogate-based modelling approach, which captures all relevant uncertainty, may be preferable to the use of immature survival data. Several additional sources of heterogeneity were identified as presenting potential challenges to National Institute for Health and Care Excellence appraisal, including the cost of testing, baseline risk, quality of life and routine management costs. We concluded that a range of alternative approaches will be required to address different sources of heterogeneity to support National Institute for Health and Care Excellence appraisals. An exemplar case study was developed to illustrate the nature of the assessments that may be required.

CONCLUSIONS

Adequately designed and analysed basket studies that assess the homogeneity of outcomes and allow borrowing of information across baskets, where appropriate, are recommended. Where there is evidence of heterogeneity in treatment effects and estimates of cost-effectiveness, consideration should be given to optimised recommendations. Routine presentation of the scale of the consequences of heterogeneity and decision uncertainty may provide an important additional approach to the assessments specified in the current National Institute for Health and Care Excellence methods guide.

FURTHER RESEARCH

Further exploration of Bayesian hierarchical methods could help to inform decision-makers on whether or not there is sufficient evidence of homogeneity to support pooled analyses. Further research is also required to determine the appropriate basis for apportioning genomic testing costs where there are multiple targets and to address the challenges of uncontrolled Phase II studies, including the role and use of surrogate end points.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Evidence Synthesis programme and will be published in full in Health Technology Assessment; Vol. 25, No. 76. See the NIHR Journals Library website for further project information.

Surrogate Endpoints in Oncology: Overview of Systematic Reviews and Their Use for Health Decision Making in Mexico

OBJECTIVES

The use of surrogate endpoints (SEs) for cancer drug approval in health systems is common. The objectives of this study were to identify systematic reviews (SRs) that evaluated the correlation of SEs with overall survival (OS) in cancer drugs to analyze the applications of approved cancer drugs with SEs in Mexico and to apply the validation framework proposed by the Institute for Quality and Efficiency in Health Care (IQWiG).

METHODS

An overview of SRs was conducted according to Cochrane Collaboration methodology. Applications for approved cancer drugs with SEs in Mexico were analyzed. The IQWiG validation framework was applied to evaluate the SEs identified in the overview and in the applications in Mexico.

RESULTS

A total of 85 SRs that assessed 192 SEs for different types of cancer were selected. According to the IQWiG model, only 2.5% of the SEs analyzed in the overview and only one of the applications in Mexico could be used as surrogates for OS because the reliability (methodological quality) of the SRs and the strength of the correlation of SEs with OS was mostly low (92%) and low (correlation coefficient r ≤ 0.7; 50.5%), respectively. Of the total number of cancer drugs approved in Mexico, 19.4% used SEs.

CONCLUSIONS

Most SEs for different types of cancer could not be used as surrogates for OS according to the IQWiG model, and their use for the approval of cancer drugs in Mexico is generally not justified.

A systematic review of meta-analyses assessing the validity of tumour response endpoints as surrogates for progression-free or overall survival in cancer

BACKGROUND

Tumour response endpoints, such as overall response rate (ORR) and complete response (CR), are increasingly used in cancer trials. However, the validity of response-based surrogates is unclear. This systematic review summarises meta-analyses assessing the association between response-based outcomes and overall survival (OS), progression-free survival (PFS) or time-to-progression (TTP).

METHODS

Five databases were searched to March 2019. Meta-analyses reporting correlation or regression between response-based outcomes and OS, PFS or TTP were summarised.

RESULTS

The systematic review included 63 studies across 20 cancer types, most commonly non-small cell lung cancer (NSCLC), colorectal cancer (CRC) and breast cancer. The strength of association between ORR or CR and either PFS or OS varied widely between and within studies, with no clear pattern by cancer type. The association between ORR and OS appeared weaker and more variable than that between ORR and PFS, both for associations between absolute endpoints and associations between treatment effects.

CONCLUSIONS

This systematic review suggests that response-based endpoints, such as ORR and CR, may not be reliable surrogates for PFS or OS. Where it is necessary to use tumour response to predict treatment effects on survival outcomes, it is important to fully reflect all statistical uncertainty in the surrogate relationship.

Pre-mRNA Processing Factor 8 Accelerates the Progression of Hepatocellular Carcinoma by Regulating the PI3K/Akt Pathway

Background

The specific function of pre-mRNA processing factors (Prps) in human malignancies has not been yet investigated. The aim of the present study was to determine the impacts of Prp8 in a common human malignancy, hepatocellular carcinoma (HCC).

Materials and Methods

RT-qPCR and Western blotting were performed to measure the expression levels of Prp8 in various HCC cell lines and HCC tissues. A hepatic astrocyte line was transfected with a eukaryotic expression plasmid to overexpress Prp8. In addition, the endogenous expression level of Prp8 in HCC cells was silenced using a short hairpin RNA method, and the role of Prp8 on cell proliferation and migration was examined by Cell Counting Kit-8, wound healing assay and Transwell assays following knockdown in HCC cells, and overexpression in astrocytes.

Results

Upregulation of Prp8 expression was found to be associated with poor clinical outcomes in patients with HCC. The upregulation of Prp8 promoted cell viability, metastasis and the activity of the PI3K/Akt pathway in hepatic astrocytes cells and HCC cells. Interestingly, loss of Prp8 had no obvious impact on cell viability and migration in hepatic astrocytes, but significantly inhibit the cell malignancy of HCC cells. Functionally, the inhibition of the PI3K/Akt pathway reversed the increased cell viability and migration of HCC cells induced by Prp8 via inhibiting EMT process.

Conclusion

Collectively, the present results suggested that Prp8 served as a tumor promoter in HCC by targeting and regulating the PI3K/Akt pathway.

Assessment of Progression-Free Survival as a Surrogate End Point of Overall Survival in First-Line Treatment of Ovarian Cancer: A Systematic Review and Meta-analysis

Importance

The Gynecologic Cancer InterGroup (GCIG) recommended that progression-free survival (PFS) can serve as a primary end point instead of overall survival (OS) in advanced ovarian cancer. Evidence is lacking for the validity of PFS as a surrogate marker of OS in the modern era of different treatment types.

Objective

To evaluate whether PFS is a surrogate end point for OS in patients with advanced ovarian cancer.

Data Sources

In September 2016, a comprehensive search of publications in MEDLINE was conducted for randomized clinical trials of systematic treatment in patients with newly diagnosed ovarian, fallopian tube, or primary peritoneal cancer. The GCIG groups were also queried for potentially completed but unpublished trials.

Study Selection

Studies with a minimum sample size of 60 patients published since 2001 with PFS and OS rates available were eligible. Investigational treatments considered included initial, maintenance, and intensification therapy consisting of agents delivered at a higher dose and/or frequency compared with that in the control arm.

Data Extraction and Synthesis

Using the meta-analytic approach on randomized clinical trials published from January 1, 2001, through September 25, 2016, correlations between PFS and OS at the individual level were estimated using the Kendall τ model; between-treatment effects on PFS and OS at the trial level were estimated using the Plackett copula bivariate (R2) model. Criteria for PFS surrogacy required R2 ≥ 0.80 at the trial level. Analysis was performed from January 7 through March 20, 2019.

Main Outcomes and Measures

Overall survival and PFS based on measurement of cancer antigen 125 levels confirmed by radiological examination results or by combined GCIG criteria.

Results

In this meta-analysis of 17 unique randomized trials of standard (n = 7), intensification (n = 5), and maintenance (n = 5) chemotherapies or targeted treatments with data from 11 029 unique patients (median age, 58 years [range, 18-88 years]), a high correlation was found between PFS and OS at the individual level (τ = 0.724; 95% CI, 0.717-0.732), but a low correlation was found at the trial level (R2 = 0.24; 95% CI, 0-0.59). Subgroup analyses led to similar results. In the external validation, 14 of the 16 hazard ratios for OS in the published reports fell within the 95% prediction interval from PFS.

Conclusions and Relevance

This large meta-analysis of individual patient data did not establish PFS as a surrogate end point for OS in first-line treatment of advanced ovarian cancer, but the analysis was limited by the narrow range of treatment effects observed or by poststudy treatment. These results suggest that if PFS is chosen as a primary end point, OS must be measured as a secondary end point.

Anti-NaPi2b antibody-drug conjugate lifastuzumab vedotin (DNIB0600A) compared with pegylated liposomal doxorubicin in patients with platinum-resistant ovarian cancer in a randomized, open-label, phase II study

Background

Lifastuzumab vedotin (LIFA) is a humanized anti-NaPi2b monoclonal antibody conjugated to a potent antimitotic agent, monomethyl auristatin E, which inhibits cell division by blocking the polymerization of tubulin. This study is the first to compare an antibody-drug conjugate (ADC) to standard-of-care in ovarian cancer (OC) patients.

Patients and methods

Platinum-resistant OC patients were randomized to receive LIFA [2.4 mg/kg, intravenously, every 3 weeks (Q3W)] or pegylated liposomal doxorubicin (PLD) (40 mg/m2, intravenously, Q4W). NaPi2b expression and serum CA-125 and HE4 levels were assessed. The primary end point was progression-free survival (PFS) in intent-to-treat (ITT) and NaPi2b-high patients.

Results

Ninety-five patients were randomized (47 LIFA; 48 PLD). The stratified PFS hazard ratio was 0.78 [95% confidence interval (95% CI), 0.46-1.31; P = 0.34] with a median PFS of 5.3 versus 3.1 months (LIFA versus PLD arm, respectively) in the ITT population, and 0.71 (95% CI, 0.40-1.26; P = 0.24) with a median PFS of 5.3 months versus 3.4 months (LIFA versus PLD arm, respectively) in NaPi2b-high patients. The objective response rate was 34% (95% CI, 22% to 49%, LIFA) versus 15% (95% CI, 7% to 28%, PLD) in the ITT population (P = 0.03), and 36% (95% CI, 22% to 52%, LIFA) versus 14% (95% CI, 6% to 27%, PLD) in NaPi2b-high patients (P = 0.02). Toxicities included grade ≥3 adverse events (AEs) (46% LIFA; 51% PLD), serious AEs (30% both arms), and AEs leading to discontinuation of drug (9% LIFA; 8% PLD). Five (11%) LIFA versus 2 (4%) PLD patients had grade ≥2 neuropathy.

Conclusion

LIFA Q3W was well tolerated and improved objective response rate with a modest, nonstatistically significant improvement of PFS compared with PLD in platinum-resistant OC. While the response rate for the monomethyl auristatin E-containing ADC was promising, response durations were relatively short, thereby highlighting the importance of evaluating both response rates and duration of response when evaluating ADCs in OC.

Clinical trials.gov

NCT01991210.

C-Terminus of E1A Binding Protein 1 Stimulates Malignant Phenotype in Human Hepatocellular Carcinoma

<strong>BACKGROUND</strong> The C-terminus of E1A binding proteins (CTBPs) has recently been shown to stimulate tumorigenesis in several human tissues by participating in cell signal transduction. However, to date, the expression profile of CTBP isoforms in hepatocellular carcinoma (HCC) and the impact of CTBPs on HCC cell phenotype have not been fully explored. <strong>MATERIAL AND METHODS</strong> The expression level of CTBP1 was investigated in various HCC cell lines and HCC tissues by RT-qPCR, Western blotting, and immunohistochemistry assays. The phosphatidylinositol-3-kinase (PI3K) inhibitor LY294002 was utilized to treat hepatic astrocyte cells, and the impact of CTBP1 on proliferation and metastasis of hepatic astrocytes and HCC cells was accessed by CCK-8, clone-forming, Transwell chamber, and cell scratch assays. <strong>RESULTS</strong> Increased expression of CTBP1 was observed in HCC tissues and was a predictor of poor prognosis in HCC patients. CTBP1 modified proliferation and migratory activity of HCC cells via the PI3K/protein kinase B (Akt) signaling pathway in hepatic astrocytes. Moreover, genetic loss of CTBP1 significantly reduced the metastatic activity of HCC cells <i>in vitro</i>. <strong>CONCLUSIONS</strong> Our data suggest that the loss of CTBP1 suppresses cell proliferative and invasive activity of HCC cells via the PI3K/Akt pathway.

A Systematic Review and Recommendation for Reporting of Surrogate Endpoint Evaluation Using Meta-analyses

Background

Meta-analysis of randomized controlled trials (RCTs) has been widely conducted for the evaluation of surrogate endpoints in oncology, but little attention has been given to the adequacy of reporting and interpretation. This review evaluated the reporting quality of published meta-analyses on surrogacy evaluation and developed recommendations for future reporting.

Methods

We searched PubMed through August 2017 to identify studies that evaluated surrogate endpoints using the meta-analyses of RCTs in oncology. Both individual patient data (IPD) and aggregate data (AD) meta-analyses were included for the review.

Results

Eighty meta-analyses were identified: 22 used IPD and 58 used AD from multiple RCTs. We observed variability and reporting deficiencies in both IPD and AD meta-analyses, especially on reporting of trial selection, endpoint definition, study and patient characteristics for included RCTs, and important statistical methods and results. Based on these findings, we proposed a checklist and recommendations to improve completeness, consistency, and transparency of reports of meta-analytic surrogacy evaluation. We highlighted key aspects of the design and analysis of surrogate endpoints and presented explanations and rationale why these items should be clearly reported in surrogacy evaluation.

Conclusions

Our reporting of surrogate endpoint evaluation using meta-analyses (ReSEEM) guidelines and recommendations will improve the quality in reporting and facilitate the interpretation and reproducibility of meta-analytic surrogacy evaluation. Also, they should help promote greater methodological consistency and could also serve as an evaluation tool in the peer review process for assessing surrogacy research.